Press



March 9, 1937. Y RL N 2,073,239

PRESS Filed April 30, 1934 -2 Sheets-Sheet l ATTO R N EY March 9, 1937.A. A. BYERLEIN PRESS Filed April 30, 1934 2 Sheets-Sheet 2 iii INVENTORMM Q d e/111M,

ATTORNEY Patented Mar. 9,-1937' UNITED STATES PRESS Arthur A. Byerlein,Detroit, Mich., assignor to General Machinery Corporation, Hamilton,Ohio, a corporation of Delaware Application April :0, 1934, Serial No.123,133

Claims.

This invention relates to power presses, and more particularly topresses for drawing or forming sheet metal or the like.

One object of the invention is the provision of 5 a power press having awork forming slide which is alternately operated by a high speed drivingconnection to a power source and a lowspeed driving connection to apower source to obtain a comparatively low speed of movement of theslide during the work forming or drawing part of the cycle of pressoperations.

Another object of the invention is the provision of a press for drawingor working metal, having a plurality of driving connections ineluding aplurality of .clutches which are automatically operated in timedrelation with the slide so as to connect the driving motor alternatelythrough a high speed and a lowspeed driving connection to a powersource.

Other objects and advantages of the invention will ,be apparent from thefollowing description, the appended claims and the accompanyingdrawings, in which- Fig. 1 is a front elevation of a power pressembodying the present invention, a part of the lower portion of thepress being omitted;

Fig. 2 is a side elevation of the upper part of the press;

Fig. 3 is a section on the line 3-4 of Fig. 2; Fig. 4 is a diagrammaticshowing of the electrical control system; and

Fig. 5 is a partly diagrammatic view of the control switches and theiroperating cams.

Conventional drawing presses are driven from an operating shaft whichrotates at a uniform rate of speed, for example at the rate of about sixstrokes per minute which has been found to be about the most economicalrate for certain uses. a higher rate of speed is employed it is found.that the number ofbroken stampings,

due lare ly to high drawing speed, is unduly increased. The breakage canbe reduced by lowering the number of strokes per minute but then thetotal production in any. given time period.

will also be reduced. In accordance with the present invention, however,the operating shaft by means of'which the movable slide is driven,

is so operated that the speed of the plunger is materially slower duringthe drawing part of a cycle of press operations in order that acomparatively high number of strokes per minute is attained withoutcorrespondingly increasing the speed of the drawing operation itself.

The press may be of any suitable character having a movable slide whichcarries the die for drawing or otherwise forming the work, and may beequipped. with the usual air pressure controlled slide and have anydesired number of mechanically moved slides for serving as blank holdingmembers, forming members. etc. As 5 herein shown the press is providedwith a plurality of mechanically operated upper slides l l and .I2 andthe mechanically operated lower slide 42, which are moved in timedrelationship as more fully set forth in my prior United States i0Patents'No. 1,768,503 and No. 1,967,464.

Referring more particularly to the drawings, I Q designates generallythe frame of the press in which the slides H and I! are mounted forreciprocatory movement that the slide ll may 15 descend first and dwellfor a period of time while the die carried by the slide I! is eflectivein drawing the metal. The slides II and- II, as

- shown, are operated by a system of toggle levers,

both having a dwell period by reason of the 20 relative arrangement ofthe centers of the various operating parts.

Rotatably mounted in an upper portion of the press frame is a poweroperated driving shaft It. This shaft is rotated bytwo gears l4 and i525 each of which meshes with a pinion It provided at opposite ends of ashaft II which also carries a gear H. The gear I! meshes/with thedriving pinion I! provided on a transverse shaft 20. This shaft 20,aswill be more fully described, is 30 operated at comparatively high speedor at comparatively low speed from an electric motor 2|.

The gears i4 and II are each provided with an eccentric stud 25 which isconnected by an arm 26 to a vertically reciprocatory slide block 3521,-the two slide blocks, one at either side of the frame, beingconnected to the four-rock shai't extensions 28 which are rigid with thetoggle arms 30, the latter bein pivotally connected to the toggle links3| and operating the 40 inner slide II. The connection between the crankshaft ll'and the blank holding slide II is eflective through togglelinks 32 which are connected to toggle arms rigid with the two rockshafts 33 which are operated from the slide 3! 45 driven by operatingmeans connected to the crank throw 18, as more fully explained in myprior patent and patent application referred to above.

During the time the slide i2 is dwelling it may itself serve as a blankholder together with a slide I I while the'work is being operated uponby a die which is mounted for reciprocatory movement in a lower portionof the press. Such lower diemaybeoperatedbymeansofthelower die 55carrying slide designated generally 42, Slide 42 is guided for verticalmovement, its opposite ends being connected to operating rods 48, theupper ends of which are formed as eccentric straps 49 engaged with thecylindrical surfaces 40 that are eccentrically provided at opposite endsof the operating shaft. l3.

The motor 2| is connected by means of a driving belt 50 or the like to aflywheel 5| which is freely rotatable on antifriction bearings 52provided on an operating shaft 53, as shown in Figs. 1 and 3. The shaft53 is rotatably supported in bearing portions 54 of the frame, one endof the shaft being fixed to a gear pinion 55 which meshes with gear 56fixed on one end of shaft 20. The flywheel may be placed in drivingconnection with shaft 53 by means such as the magnetic clutch 51. Asherein shown the clutch comprises a flexible plate member 58 secured tothe shaft 53 and adapted to be held between the driving plates 59 and 68when the clutch energizing coil 6| is supplied with electric current.

The clutch energizing supply comes in through wires 62 connected toconductor rings 63 engaged by brushes 84. When the clutch isengaged, theflywheel 5| and theshaft 53 move at the same speed of rotation, and theoperating shafts 28 and 3 are driven at a comparatively low speedsuitable for .metal drawing operations.

Rotatably mounted at the other end of the shaft 53 is a sleeve 66 whichis rotatably mounted in a bearing portion 54 of the frame. On the outerend of the sleeve is fixed a gear 68 that meshes with a gear 69 fixed onshaft 28. sleeve, which can rotate freely on the shaft 53, may becoupled up to the flywheel 5| by means of a magnetic clutch I0 which isgenerally similar in construction to the magnetic clutch provided ontheopposite end of the flywheel.

At one end of the shaft 20 is a brake wheel adapted to be engaged by abrake shoe 12 under the action of a spring 13. The spring is compressedand the brake shoe '|2 moved to a released position by means of anelectro-magnet 14 when the electro-magnet is energized.

The two clutches 51 and I8, and the magnetic brake, are automaticallycontrolled in proper timed relation with the movements of the slide bymeans of a switch system that has been illustrated diagrammatically inFigs. 4 and 5. This switch system includes a sprocket gear 16 driven bya sprocket chain 11 from the crank shaft l3, the sprocket gear beingconnected so as to operate at the same speed as the crank shaft 3. Threecams 18, I9 and are fixed to the shaft 8| on which the sprocket gear 16is provided,

and serve respectively for the control of switches 8|, 82 and 83. Theseswitches are providedat a suitable location on the frame in a cam and 0switch box. When the slide I2 is at its uppermost position, the switch8| is closed and remains closed until the slide has descended. At thestart of a cycle of operations, with the slide in its uppermostposition, the switches 82 and 5 83 are open.

The power source S, as shown in Fig. 4, is conn ected through stopswitches 85 which are normally closed but which may be operated by theattendant in case of emergencies. In series with 70 the switches 85 area plurality of starting switches 86 two of which are closed by the twohands of one attendant while the other two are closed by the hands ofthe second attendant when a cycle of operations is to be started. Before75 these switches are closed, however, one of the The operators hasmoved a drum type switch 81 so as to interconnect the points a, b, c andd together and to interconnect points e and f together. With the drumtype switch in position for starting operations, and with the severalswitches 86 closed, current is supplied from one side of the line S to arelay 84 which when energized closes the connection from the line S toone side of the magnetic clutch elements 6| and 93, and to one side ofthe brake winding 14. Current also flows through the closed switch 8|toa relay 88 which is energized so as to complete a circuit from oneside of the line S through wire 89 to the coil 6| of the magnetic clutch51. The circuit lsthus completed through winding 6| and the magneticclutch 51 connects the slide through the low speed gear drive to theflywheel.

The shaft I3 is therefore operated at comparatively low speed, suitablefor press forming operations, switch 8| remaining closed and switch 83closing at about 90 degrees, rotation of the crank shaft. When switch 83closes it short circuits the manually operated push buttons or switches86 so that the operators can remove their hands and current willcontinue to be supplied through switch 83 to the relay 88. When theslide reaches its lower limit of movement, and after it has completedits metal forming operation, the switch 8| opens and at the same timeswitch 82 closes. When switch 8| opens the winding 6| of the magneticclutch 51 is deenergized, but the closing of the switch 82 has energizedrelay 90 and completed a circuit from one side of the line to a lead 9|which is connected to the winding 93 of magnetic clutch 61. The flywheelis therefore connected through the high speed drive gearing includingthe gears 68 and 69 so as to move the slide at comparatively high speedas the slide moves up away from the work. Just before the slide reachesits upper limit 'of travel, the cams I9 and 80 are efiective on theswitches 82 and 83 to open both of these switches. This deenergizes themagnetic clutch 51. At the same time this happens, the switch 8| isagain closed, but the winding 6| of the magnetic clutch 51 is notenergized since the push buttons 86 are open and switch 83 has beenopened. When the switch 83 opens it interrupts a flow of current throughcontact 0 and lead 95 and deenergizes a relay 98 which was closed toenergize the brake releasing winding 14 when the push buttons 86 werefirst closed by the operators. The deenergization of the winding 14causes the brake to be applied, thus stopping the press ready for asecond cycle.

When setting dies it is necessary to move the plunger 9. small amount ata time and to provide for such operation, or inching as it is termed,the drum switch 81 is rotated to interconnect points f, g and h, whichconnects the inching switch 98 ahead of the starting buttons 86 andahead of the cam operated switch 83. The inching switch 98 may be closedby the operator so as to connect one side of the line directly through alead 99 to energize the relay 88 and through a lead I80 to energize therelay 84 in'order to energize the magnetic clutch 51.

It will now be apparent that when the operator so desires, he can startthe press in operation by closing the push buttons 86. The press willthen start moving at comparatively low speed suitable for metal drawing,and will continue to move at such low speed until the metal forming iscompleted. The magnetic clutches will then be automatically operated sothat one is engaged and the other is disengaged in order to cause anincrease of press speed during the non-effective part of the cycle ofoperations while the slide moves upwardly. At the end of a cycle ofoperations the press is automatically stopped by means of the brake.Inasmuch as the non-effective parts of the cycle of press operations arecarried out quickly the number of strokes per minute of the press can beconsiderably higher than the conventional speed of operation while stillmaintaining a suitable low speed of operation during the work drawingparts of the cycle.

While the form of apparatus herein described constitutes a preferredembodiment of the in-- vention, it is to be understood that theinvention is not limited to this precise form of apparatus, and thatchanges may be made therein without departing from the scope of theinvention which is defined in the appended claims.

What is claimed is: I

1; A press comprising a frame, a metal drawing slide reciprocablymounted therein, an operating shaft for said slide, mechanism positivelyconnecting said slide and shaft for timed operation throughout acomplete revolution of said shaft,

drive means for operating said shaft at high speed, drive means foroperating said shaftat low speed, a motor for operating said drivemeans, and means operable in timed relation with said shaft for engagingsaid motor with said drive means to obtain low speed movement of saidshaft and said slide during the metal drawing part of a cycle of pressoperations and high speed movement of said shaft and said slide afterthe metal drawing part of a cycle.

2. A press comprising a frame, a metal forming slide reciprocablymounted therein, a rotatable operating shaft for said slide, mechanismpositively connecting said slide and shaft for timed operationthroughout a complete revolution of said shaft, a motor, a highspeedoperating connection between said-motor and said shaft including aclutch, a low speed operating connection between said motor and saidshaft including a second clutch, and means operable in timed relationwith said shaft for alternately engagingsaid clutches to obtain lowspeed press operation throughout the period in the press cycle while theslide moves in one direction and to obtain high speed press operationthroughout the period in the press cycle while the slide moves in theother direction.

3. A drawing press comprising a frame, a slide reciprocably mountedtherein, a rotatable operating shaft for said slide, mechanismpositively shaft to obtain high speed movement of said shaft.

timing means movable in timed relation with said shaft, .and a switchsystem controlled by said timing nieans and automatically controllingthe connection between said motor and said drive means, said timingmeans and switch means providing for low speed operation of the slideduring the drawing part of a cycle of operations and providing for-highspeed operation of said slide while the slideis moving away from thework.

4. A press comprising a frame, a metal drawing slide reciprocablymounted therein, an operating shaft for said slide, mechanism positivelyconnecting said slide and shaft for timed operation throughout acomplete revolution of said shaft, a motor, gearing foroperating saidshaft at low speed, a magnetic clutch for coupling said gearing to saidmotor, a second gearing for operating said shaft at high speed, a secondmagnetic clutch for coupling said motor to said second gearing,

means operable in timed relation with said shaft for automaticallycontrolling said clutches to obtain low speed movement of the slideduring the work forming part of a press cycle and high speed movement ofthe slide after the work forming part of a press cycle.

5. A drawing press comprising a frame, a blank holder slide and a metaldrawing slide mounted for reciprocatory movement in said frame, a.rotatable operating shaft, mechanism positively connecting said slidesand said shaft and providing a dwell in the operation of the blankholder slide in fixed timed relation with respect to the movements ofthe drawing slide, a motor,'drive means operably connecting said motorto said shaft for operating said shaft at a comparatively low speed,drive means operably connecting-said motor to said shaft for operatingsaid shaft at comparatively high speed, and means operable in timedrelation with said shaft for alternately enaging said motor with saiddrive means to obtain a comparatively low speed movement of said drawingslide throughout the metal drawing. part of a cycle of operation and toobtain comparatively high speed movement of said slides while movingaway from the work piece after the com-

